The present invention relates in general to printed circuitry and more particularly to an improved printed circuit board arrangement especially suited for use in miniaturized electronic apparatus wherein a main or master circuit board and associated components may be used to provide predetermined operational capabilities with other operating features being provided by separate option circuit boards selectively interconnectable with the main chassis board.
Printed circuitry of one sort or another has been incorporated in a wide variety of electrical and electronic devices. It is particularly advantageous however for use with miniaturized electronic apparatus where space is critical and bulky wire-to-wire connections cannot be easily tolerated.
Portable, hand-held, two-way communications provides a particular advantageous application for printed circuitry and their attendant associated printed circuit boards. A single basic or master circuit board can be designed to retain the various required electronic components for the transmitter and receiver portions thereof, and planned or laid out as to effect the various intercircuit connections to make the apparatus as a whole functional, all with minimum space and optimized efficiency. One disadvantage, however, is that the printed circuit chassis board, once designed and laid out, is thereby fixed operationally, and not readily adaptable to meet any additional or alternative operational features.
For example, in the portable two-way communications unit above-referenced, if tone coded squelch operation is required, or if automatic unit identification is to be effected upon interrogation from some centralized location, then it would be expected that an entirely different chassis board would need to be designed so as to implement the desired function in addition to the conventional transmit and receive operation. It will be readily appreciated that this creates an added inventory burden, i.e., a different circuit board for each combination of operational capabilities, increases costs unnecessarily, is inefficient, inflexible, and may well impair reliability.